Rashidun Caliphate

Muhammad died in 632, and within thirty years the community he left ruled from Libya to eastern Iran. Four caliphs took the title of “successor” in turn — Abu Bakr, who held Arabia together through the riddah wars; Umar, under whom the armies broke both of the great powers of the age; Uthman, who fixed the text of the Quran; and Ali, the Prophet’s cousin and son-in-law. The Sasanian Persian Empire, four centuries old, was conquered entirely between 633 and 654: Qadisiyya in 636 opened the road to the capital at Ctesiphon, and the last Sasanian emperor, Yazdegerd III, died a fugitive in 651. From the Byzantines the caliphate took Syria after the Battle of Yarmuk in 636, then Palestine and Egypt, with Alexandria falling by 641–642. It was one of the fastest large conquests in recorded history, run by a generation of men who had known Muhammad personally.

The same speed that built the empire did not hold it. Umar was stabbed by a Persian slave in 644. Uthman was killed by rebel soldiers in his own house in 656, and his death opened the First Fitna — the first Muslim civil war. Ali, the fourth caliph, fought rivals including Mu’awiya, the governor of Syria, and in 661 a Kharijite assassin killed Ali at prayer. Power passed to Mu’awiya, who founded the Umayyad dynasty and made the caliphate hereditary. The Rashidun is revered in Sunni Islam as a golden age, the one period when the community was led the way the Prophet had led it, and the quarrel over who should have succeeded Muhammad became the root of the Sunni–Shia split that is still alive fourteen centuries later. The memory has not died. The caliphate itself ended in 661.